A few things to remember about Venezuela:

1.
Venezuela's wealth was built on oil. With this oil-money, Hugo Chavez built a generous socialist state with lots of social spending for the lower classes.
He did not set aside monetary reserves.
He did not upgrade and maintain Venezuela's infrastructure.
He did not diversify Venezuela's economy.

2.
Saudi-Arabia massively increased their oil-output in 2009 to drop the price of oil and to bankrot the upcoming fracking-industry in the US. (They failed.)
As a result of the price-drop, countries like Russia and Venezuela suffered major financial losses.
IIRC in 2017 or 2018 Saudi-Arabia and Iran tried to negotiate a reduction of oil-production to increase the price, but the deal was never made because they didn't trust each other.

3.
Venezuela now had a drastically reduced income, no reserves and expenditures it couldn't cut without causing massive political trouble. The solution would have been economic and currency-reforms, however those were ideologically forbidden because that would have meant admitting that Chavez-Socialism isn't the best form of government in the world.

4.
In 2010, Maduro created new seats on the Supreme Court and stacked them with loyalists.
https://en.wikipedia.org/wiki/Supreme_Tribunal_of_Justice_(Venezuela)

5.
In 2015, the opposition won the parliamentary elections, even though Maduro's party had a massive advantage in terms of media. https://en.wikipedia.org/wiki/2015_Venezuelan_parliamentary_election

6.
In 2016, the Supreme Court (stacked with Maduro-loyalists) relieved the parliament of its powers because they had seated candidates whose elections the Supreme Court had declared faulty.

7.
In 2017, Maduro held elections for an assembly that would write a new constitution. The opposition boycotted it. His party won. The company that provided the voting-machines later declared that the result had been tampered with by election-officials.
https://en.wikipedia.org/wiki/2017_Venezuelan_Constituent_Assembly_election

8.
That assembly, whose job was to write a new constitution, quickly effectively became a second parliament (dominated by Maduro-loyalists), passing laws and conducting oversight.

9.
In early 2018, Maduro was reelected president in an election widely regarded as fraudulent.
https://en.wikipedia.org/wiki/2018_Venezuelan_presidential_election

10.
In late 2018, Maduro created a new executive council that would support the office of the president. It was headed by him, Maduro, the president. The council was hailed as the ultimate expression of the will of the people. (Even though being unelected.) And it gave Maduro direct and local access to all civilian and military forces, meaning that Maduro can now directly give soldiers orders, circumventing the military chain of command.

11.
Citing the fraudulent election, the parliament declares Juan Guaido president as Maduro is about to be sworn in.










But the US doesn't like him, so Maduro must be one of the good guys.
Like Gaddafi.